She'd embark on an epic swansong around the world as secretary of state, a dizzying itinerary of east-west and north-south flights that would take her past 1 million miles in the air at the helm of American diplomacy and perhaps break her own record of 112 countries visited while in the post. Then, there would be a long rest, time and work with her husband, former President Bill Clinton, on development issues and a sequel to her 2003 memoir "Living History."

Finally, she'd make a destiny-defining decision: whether to try again to become America's first female president.

Her health got in the way: a nasty stomach virus while returning from a weeklong trip to Europe, exhaustion, severe dehydration, a faint, a fall and a concussion that led to a brief hospitalization when doctors discovered a blood clot near her brain. The woman who'd seemed to lay the perfect groundwork for another presidential bid - indeed, who'd made a life carving out her own path - was sidelined by circumstances beyond her control.

It was a rare sign of vulnerability in what had been a carefully charted four years of often grueling overseas travel and behind-the-scenes politics, where as a peace mediator, international enforcer and global ambassador of America she fully emerged from the giant shadow of her husband. But it was not the only sign.

BURDEN OF BENGHAZI

The deadly terrorist attack on the U.S. Consulate in Benghazi, Libya, on Sept. 11, 2012, revealed an episode of State Department miscommunication on her watch that could feed into her diplomatic legacy and give future political opponents, should she return to politics, an opening to exploit.

And so, when she testified to Congress about the attack, both the drive and the drama forever associated with the Clintons were suddenly back. In the final spectacle of a diplomatic career that ended Friday when John Kerry succeeded her, she would not be browbeaten.

Pressed perhaps once too often on why the terrorist assault was miscast as a public protest in the days afterward, Clinton went after her Republican inquisitor with her voice rising and quivering in anger. "What difference, at this point, does it make?" she demanded. "It is our job to figure out what happened and do everything we can to prevent it from ever happening again, Senator."

On Thursday, Clinton denounced those who still insist the administration lied about the attack.

"There are some people in politics and in the press who can't be confused by the facts," she told The Associated Press in her last one-on-one interview as secretary of state. "They just will not live in an evidence-based world. And that's regrettable. It's regrettable for our political system and for the people who serve our government in very dangerous, difficult circumstances."

Whatever the merits of the arguments, Clinton's responses confirmed she had lost none of the vigor that had taken her from defeated Democratic Party presidential candidate to one of the world's most popular and recognizable women.

And, it suggested that despite her recent health troubles, the former senator and first lady was intent on keeping her political future in her own hands, even as she laughed off attempts to coronate her as a candidate-in-waiting.

"I am still secretary of state, so I'm out of politics," Clinton told CBS' "60 Minutes" in a joint interview with President Barack Obama last weekend. She cracked: "I'm forbidden from even hearing these questions."

But as Clinton was leaving office, the very appearance of two former foes so close and so amicable only seemed to underscore Clinton's eventual succession - if she wants it.

WEIGHING 2016

Even before her ailments, people close to her were debating the pros and cons of another presidential run. Would it be worth the cost in time, energy and especially money - her 2008 campaign debt was just retired in January - and would it spark a new round of personal attacks on her, her husband and her character?

Polls show her as the popular favorite for 2016; no Democrat is better placed right now to unify the party. With instant national appeal and the highest approval ratings of her political career, she would also presumably have a head start on any Republican candidate in a general election. And at age 69, she'd hardly be too old to lead. She'd be five years younger than Vice President Joe Biden, a possible party rival.

Yet any sense of inevitably is decidedly premature. After all, Clinton was considered the prohibitive favorite for the 2008 Democratic nomination for several years, right up until Obama beat her in Iowa. Like Obama, some of the potential contenders for 2016 are largely unknown quantities whose strengths cannot yet be measured.

There's no question Clinton's years as a well-regarded senator and especially her statesmanship in the Obama administration have lifted her above the partisan fray and improved her standing with the public. Her favorability rating in polls is at its highest point in her career, 67 percent in a recent Washington Post-ABC survey, indicating that the polarization that marked her years in the White House, seen again in the 2008 campaign, has been overcome.

Some of that hard-earned respect would vanish the moment she re-emerges as the face of the Democratic Party and becomes a critical player in rancorous debates over immigration, abortion, debt, taxes, health care and more.

Inevitably, she would in some ways revert to the divisive personality, who - fairly or unfairly - in the 1990s inspired a massive campaign to defeat her "Hillarycare" health overhaul and became the first president's wife to appear before a grand jury when called on by the Whitewater investigation. That probe, the White House travel office firings, her feminist positions and the many donors to her husband's campaigns invited to stay at the White House made some voters cynical about the Clintons' integrity and moved critics to go after her in strikingly personal terms.

Clinton, of course, wasn't one to shy away from confrontation herself.

In the 2008 campaign, she called Obama a "slum landlord" representative and called out the Illinois senator with the riposte "Shame on you, Barack Obama." A decade earlier, she dismissed talk of her husband's infidelity as part of a "vast right-wing conspiracy" that had dogged him for years.

A MANGLED TALE

Now, reaction to the attack on the U.S. Consulate in Libya, in particular, is being looked at by her allies as a cautionary tale of the tone that awaits any future presidential bid. Although no investigation has specifically faulted Clinton or backed up claims of a conspiracy by the Obama administration to provide disinformation about the assault, Benghazi's timing in the final weeks of a close presidential contest led to bitter and personal criticism of Clinton in the blogosphere, on cable television and on Capitol Hill.

It went so far that some critics suggested she was faking a "diplomatic illness," as John Bolton, a former U.N. ambassador for President George W. Bush, put it, to avoid testifying on Benghazi.

"There is an obligation here, especially if Secretary Clinton decides to run for president, to indicate what happened," Bolton said.

With the country pressing for answers after Ambassador Chris Stevens and three other Americans were killed in the Benghazi attack, Clinton left the difficult task of presenting the Obama administration's response to Susan Rice, America's U.N. envoy and her would-be successor as secretary of state.

Relying on talking points drafted by U.S. intelligence, Rice delivered the now-retracted version of the consulate siege as a protest hijacked by extremists, with no evidence to suggest the attack was premeditated. Three months later, Rice was forced to withdraw from consideration to succeed Clinton because of fierce criticism from Republicans in the Senate.

WHAT'S NEXT?

Clinton seems not to have made up her mind on a presidential run, although she insists, seemingly less strenuously than before, that she is through with the high-wire of politics. Certainly many of her supporters, who just days ago launched a super PAC to support another presidential run, want her to go for it.

At a September meeting in New York, Israeli Prime Minister Benjamin Netanyahu asked her: "What are you going to do?" It was an apparent reference to her post-secretary plans. Clinton shook her head and said, "I don't know."

Asked on the eve of her departure from the State Department if she still had contributions to make, she replied "Absolutely," but stressed that the how and when were not yet clear.

"I haven't decided yet," she told the AP. "I really haven't yet. I have deliberately cabined it off. I am going to be secretary of state until the very last minute when I walk out the door. And then I am going to take the weekend off and then I may start thinking about all the various offers and requests and ideas that have come my way."

In the final months of her tenure as secretary of state, Clinton helped secure a cease-fire between Israel and the Palestinian militant group Hamas in the Gaza Strip and ordered a series of changes in the operations of her department in response to the Benghazi attack.

She also has remained committed to core interests such as women and children in developing economies and civil society in repressive countries - issues she has tried to elevate to an equal diplomatic footing with peace processes and trade talks.

THE BILL SHADOW

It was not always an easy path. Early on as secretary, amid talk that she was losing influence within the administration, Clinton embarked on a lengthy trip to Africa to highlight those issues, only to be upstaged by the arrival of her husband and his entourage in North Korea to free two American journalists.

Despite a historic visit to war-ravaged Goma in the Democratic Republic of Congo, the seven-nation, 11-day tour of the continent is best remembered for her testy exchange with a student in Kinshasa who asked what Bill Clinton thought about Chinese influence in Africa. "You want me to tell you what my husband thinks?" she asked. "My husband is not the secretary of state. I am. So, you ask my opinion, I will tell you my opinion. I'm not going to be channeling my husband."

In one early embarrassment, she presented a Russian official with a button that was supposed to say "reset," conveying the Obama administration's wish to mend ties with the Kremlin. The button had been erroneously translated into Russian and read "overcharged."

Melanne Verveer, a longtime Clinton confidante who became the first U.S. ambassador at-large for women's issues, once said her friend had an "absolute tin ear for foreign languages." But Clinton has long realized the value of listening, in any language, and made it a point to hear out longwinded comments, not just from leaders but ordinary people, in her travels. Clinton held nearly 60 town hall-style events abroad while she was secretary, taking questions on topics ranging from her hairstyle and marriage to drone strikes in Pakistan.

VOICE OF HER OWN

And, she has not been shy in speaking her mind.

At an event in Pakistan in 2009, Clinton said she found it hard to believe that no one in the Pakistani government knew where Osama bin Laden was, prompting an outcry. Again, in Pakistan Clinton defended deeply unpopular drone strikes against militant targets.

On her first trip abroad as secretary of state, Clinton raised eyebrows by saying that differences over human rights could not hold the entire U.S.-Chinese relationship hostage. This upset human rights activists, who had been sympathetic to her presidential bid.

Clinton stuck to her guns, though, and three years later, she was able to negotiate the release of the blind Chinese lawyer who had taken refuge at the U.S. Embassy in Beijing, while re-opening a human rights dialogue with Beijing.

It was one of her biggest diplomatic triumphs, alongside her historic trip to Myanmar. With signs of the long-repressive regime opening, Clinton in December 2011 became the first secretary of state in 56 years to visit the country, urging it along its reform path and sitting down with the long-imprisoned opposition leader Aung San Suu Kyi.

She traveled to every country in Southeast Asia in the end, strengthening ties with old enemies from the Vietnam War and showing China that it wouldn't be able to steamroll its smaller neighbors in maritime and other disputes without also facing U.S. resistance.

Successes also included a tenuous oil deal between Sudan and South Sudan, persuading China and others to implement crippling oil sanctions against Iran and elevating gay rights - much like she did with women's rights in the 1990s - to a new level of global credibility.

MISSIONS UNACCOMPLISHED

Yet Clinton leaves with many international crises unresolved, such as Syria's civil war and Egypt's democratic future. The U.S.-Israel alliance is on shaky ground, terrorism is on the rise in North Africa, there's an unclear endgame to the Afghanistan war and Israelis and Palestinians are no closer to a two-state peace solution than they were four years ago. And, despite endless warnings, Iran's nuclear program has moved closer to weapons capacity.

In all, Clinton spent 401 days on overseas travel and almost three months in the air.

Oftentimes she made a splash in the world without even trying.

In Italy, an impromptu 2011 shopping expedition to the Salvatore Ferragamo store with her aide de camp, Huma Abedin, caused a major traffic tie up in central Rome. A visit to ancient ruins at Cambodia's famed Angkor Wat temple complex turned the heads of hundreds of other tourists.

Photos of her drinking a beer at a bar in Colombia made newspaper front pages. A video of her dancing at a dinner in South Africa became a hit online as did the "Texts from Hillary" meme, featuring a photo of a stern-looking Clinton peering through sunglasses at her Blackberry while aboard a military plane en route to Libya.

A village in India is named for her. In 2010 in Kosovo, Clinton's motorcade made an impromptu stop at a store called "Hillary" just a stone's throw from a statue of her husband on the main road from the airport to the capital of Pristina. She happily posed for pictures there with her entourage.

She dealt confidently with the first major hiccup of her watch, the release of hundreds of thousands of classified State Department cables by WikiLeaks, which caused deep embarrassment as it laid bare confidential and often harsh assessments of foreign leaders by U.S. diplomats around the world and put at least several informants at risk.

Aside from her recent health scare, Clinton has not been immune from personal tragedy while serving as top diplomat.

One of her foreign policy mentors, the diplomat Richard Holbrooke, whom Clinton tapped to run Afghanistan and Pakistan policy, died in December 2010 after suffering a ruptured aorta during a meeting in her office. Less than a year later, Clinton's mother, Dorothy Rodham, died at the age of 92.

And, Clinton's own painful memories of marital discord were rekindled in the summer of 2011 when Abedin's husband, former Rep. Anthony Weiner, D-N.Y., was forced to resign from Congress after a sexting scandal.

Yet, her four years as secretary of state also yielded personal triumphs. From her daughter's wedding in July 2010 to her emotional get-together with Suu Kyi in Yangon and separate meetings with ailing South African icon Nelson Mandela, a personal idol, Clinton rode the crest of a wave of popularity she had not seen in her public career before.

"Get into the arena, stand up for what you believe and put together the arguments that can win the day," she told the AP as she prepared to leave office, imparting advice to anyone who might be considering a career in politics.

"I am making no decisions, but I would never give that advice to someone that I wouldn't take myself, she said. "If you believe you can make a difference, not just in politics, in public service, in advocacy around all these important issues, then you have to be prepared to accept that you are not going to get 100 percent approval."